In a generic container transporting device according to DE 10 2008 010 895 A, a cup-shaped motor housing with a diameter substantially corresponding to the diameter of the basic body of the cylindrical column is sealingly mounted on the upper end of the column. In the motor housing, the hollow-cylindrical stator of the inner-rotor electric motor is fixed, for instance by being pressed in. In the stator the cylindrical rotor is seated on a shaft from which a shaft journal projects upwards to protrude freely from the motor housing, and carries the star wheel. The motor housing comprises two bearing brackets in which bearings (loose bearing and fixed bearing) carry the rotor shaft and support and center the axial load of the star wheel. A motor controller is accommodated in a separate sealed compartment of the motor housing into which connection cables pass from the column. The motor housing that contains the stator and the rotor can be subjected to overpressure. In the penetration area of the shaft journal a rotary seal is arranged in a cover plate of the motor housing. It is complicated to exchange the electric motor, components thereof, or the star wheel, above all for the reason that access is limited and must be manipulated on many fastening elements and structural components. The rotary seal that is positioned at an exposed place is prone to leakage. The column and the motor housing are complicated components and difficult to mount. Since one wishes to keep the outer diameter of the basic body of the column as small as possible, the magnetic rotary force between the stator and the inner type rotor acts on a relatively small diameter, which inexpediently restricts the torque output of the electric motor.
It is known from EP 1 751 008 A that a plurality of elements for manipulating a plurality of containers, each in the form of a turntable for a container, are supported on a conveying table which is rotatingly or linearly driven in the conventional way, and each turntable is rotated hack and forth for the rotational alignment of the container around the turntable axis. An outer-rotor motor which is only cyclically driven for the rotational alignment in the one or the other rotational direction is provided as a drive unit of each turntable. The rotor of the motor is configured as a housing that can form the turntable at the same time, and it is rotatably supported on the conveying table with a separate rotary bearing while bypassing the stator. The stator contains windings and is fixed onto the conveying table.
A transportation star which is only schematically disclosed in WO 2008/145363 A, also for use in the wet area of a cleaning machine, comprises an electric-motor direct drive between the column and the star wheel. A motor housing simultaneously forms the drive housing. The electric motor is a reluctance motor or a grooveless synchronous motor having a disk-shaped rotor that is placed axially above and partly covers the disk-shaped stator. The stator has arranged therein magnetic coils on a flat iron ring that is separated from the rotor of circular disk shape with soft magnetic iron planks by an air gap so that a frictionless relative rotation should be possible.